Effective cleaning of laundry items in an automatic washing machine, be it a vertical or horizontal axis machine, may be attributable primarily to three factors: chemical energy, thermal energy, and mechanical energy. These three factors may be varied within the operational limits of a selected automatic washing machine to obtain a desired degree of cleaning.
Chemical energy may be related to the types of wash aids, e.g. detergent and bleach, applied to the laundry items. Thermal energy relates to the temperature of the laundry items, which may be established by the temperature of the wash liquid or the use of steam.
Mechanical energy may be attributable to the contact between an oscillating clothes mover and the laundry items, the contact between laundry items themselves, and the movement of washing liquid through the laundry items. Mechanical energy may be also related to the size and configuration of the clothes mover.
There may be benefits to utilizing a clothes mover having a low profile, typically referred to as an impeller, as opposed to a vertical axis agitator with a tall profile. However, low profile clothes movers may be less effective in moving laundry items than elongated agitators, particularly if the laundry load is treated in a reduced level of wash liquid.